(1) Field of the Invention
This invention relates to a process for the preparation of tris(aminomethyl)phosphine oxide and its ternary salts. More particularly, it relates to a process for hydrolyzing tris(N-carbalkoxylaminomethyl)phosphine oxides to tris(aminomethyl)phosphine oxide under alkaline conditions, whereby the product may be isolated directly or converted to one of its ternary salts.
(2) Description of the Prior Art
Tris(aminomethyl)phosphine oxide, (NH.sub.2 CH.sub.2).sub.3 PO, has hitherto been accessible only through the Gabriel synthesis from tris(chloromethyl)phosphine oxide, (ClCH.sub.2).sub.3 PO [Trostyanskaya et al., J. Gen Chem. USSR 37, 1572-74 (1967); Chem. Abstr. 68, 13084 (1968)]. In Ser. No. 964,854, we described some novel ternary salts of tris(aminomethyl)phosphine oxide having the formula (NH.sub.3.sup.+ CH.sub.2).sub.3 PO 3X.sup.-, and in Ser. No. 61,322 we described how such ternary salts can be prepared from tris(N-carbalkoxylaminomethyl)phosphine oxides, (RO.sub.2 CNHCH.sub.2).sub.3 PO, by hydrolysis with acids. The carbamate groups are difficult to cleave with any but the strongest acids, i.e. those having the formula HX, where X=halogen. A better method was needed to make this hydrolysis useful for preparing larger quantities of tris(aminomethyl)phosphine oxide.